Contaminants, such as mercury, may be removed from flue gases and from exhaust emitted from power plants by halogenated activated carbon sorbents and non-carbon sorbents. Methods to make halogenated activated carbon comprise halogenating an activated carbon sorbent and milling the halogenated activated carbon.
Halogens are typically in an aqueous solution during the halogenation process and/or milling process. Aqueous halogen solutions are corrosive and corrode moving parts of mills used to mill halogenated activated carbons. This adversely affects milling operations. For example, corroded mill parts do not function well and repeated replacements and maintenance issues slow down production. The effects on milling operations result in high costs associated with part replacement and time lost to shutting down of production lines for repair or maintenance.
In addition, present methods of making halogenated activated carbon sorbents do not produce uniformly halogenated sorbents. This greatly affects the contaminant removal efficiency of the halogenated sorbents.